/**
 *
 */
class SuperType {
  constructor() {
    this.a = 1;
  }
}
class SubType extends SuperType {
  constructor() {
    super();
    this.b = 2;
  }
}
const superType = new SuperType();
const subType = new SubType();
SuperType.prototype.d = 4;
console.log(subType);
// entries不会遍历原型属性
console.log(Object.entries(subType));
for (const obj in subType) {
  console.log(obj);
}
console.log(1);
